The invention relates to a device for adjusting the position of a sliding roof [cover] which can be raised whereby the cover is capable of moving in a sliding fashion between the closed position and the opened position relative to an opening in the roof, whereby transportation carriages for the cover are located in a manner which permits sliding on guide rails which are arranged on both sides of the opening in the roof.
On opening and prior to sliding back from its closed position, the movable cover must be raised above the level of the fixed roof surface in the case of devices of this type for adjusting the position of a sliding roof [cover] which can be raised. The mechanism which is provided for this purpose does not only have to overcome the force of gravity on the cover--which, depending on the size and nature of the cover, can be considerable--but it must also surmount the sealing forces which hold the cover firmly in order to close off the roof if the device for adjusting the position of the sliding roof [cover], which can be raised, is not to remain closed.
The devices which have become known previously for lifting up a sliding roof [cover], which can be raised, are based on the use of guide slots and pegs with the help of which the cover is directed upward. For example, DE-3801881-C2 discloses a lifting device which has a front and a rear connecting guide for raising and lowering the cover. Connecting pegs with rollers engage with the slot there, as a result of which the path is defined for the displacement of the cover. Raising of the cover now takes place, in essence, via the feature that the connecting slots in the vertical projection are designed approximately in the shape of the letter S so that, on opening, the cover is guided upward as a result of movement of the connecting pegs. The force which is directed upward is generated by the vertical component of the movement.
Another form of embodiment is disclosed in EP-A-0 480 166 in which oblique positioning of a sun-roof is achieved by raising the cover on one side with the help of a lever. At its lower end, he lever is mounted in a manner which permits turning and engages, in each case, with connecting slots via laterally installed pegs in the center and at the upper end. The connecting slots are constructed in a simple linear fashion since upward movement of the cover is already engendered as a result of raising the lever.
To the extent that they are in any case capable of being used in conjunction with devices for adjusting the position of a sliding roof [cover] which can be raised, the adjustment devices which have become known previously all have the disadvantage in common, therefore, that frictional forces--which are generated as a result of the movement of pegs in connecting slots--have to be overcome on raising or, as the case may be, lifting up the cover from its closed position. In the case of devices with curved connecting slots, moreover, the force which is to be exerted depends on the ascent angle of the curve in the vertical direction; this leads, of necessity, to the feature that upward movement of the cover is associated with a relatively large horizontal movement. As a result, not only are the weight and the nature of the cover subjected to limitations but also its shape and size. Thus with conventional devices, a relatively thick cover of correspondingly [large] weight would, for example, be capable of being lifted above the level of the fixed roof only with the exertion of large forces. In the case of the mechanisms which are known, conversely, a relatively lighter cover can be guided firmly into the closed position only with difficulty in such a way that the roof is sealed off in a rain-proof manner.